Tung Sol 6SL7 dual triode preamp tube. Made in Russia.
The best current production 6SL7 available. NOS performance and sound at a fraction of the price. Sweeten up the preamp section of that Vintage Ampeg B-15.

Tung Sol 6SN7GTB dual triode preamp tube. Made in Russia.
Super linearity, low noise, and full performance ratings make this one of the best 6SN7 tubes ever made. The sound signature is on par with 5692 types. Excellent driver tube in high-end audio applications.